<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script src="lib/react.development.js"></script>
  <script src="lib/react-dom.development.js"></script>
  <script src="lib/babel.min.js"></script>
</head>
<body>
<div class="root"></div>
</body>
<script type="text/babel">
  const root = ReactDOM.createRoot(document.querySelector('.root'));
  const p = (
          <div>
            123
            <h3>456</h3>
          </div>
  );
  const p1 = (
          <>
            <div>123</div>
            <h3>456</h3>
            <h3>789</h3>
          </>
  );
  const {Fragment} = React;
  const p2 = (
          <Fragment>
            <div>123</div>
            <h3>456</h3>
            <h3>789</h3>
          </Fragment>
  )
  //或者
  const p3 = (
          <React.Fragment>
            <div>123</div>
            <h3>456</h3>
            <h3>789</h3>
          </React.Fragment>
  )
  root.render(p2);
</script>
</html>